Indurating stone.



Patented December 15, 1903.

FFICE.

LYNN T. LEET AND CLAUDE A. O. ROSELL, OF NEW YORK, N. Y., ASSIGNORS TOCOMPOSITE STONE & BRICK COMPANY, A CORPORATION OF DELA- WARE.

lNDURAT'lNG STONE.

SPECIFICATION forming part of Letters Patent No. 747,193, dated December15, 1903.

Application filed February 2, 1903. Serial No. 141,585. (No specimens.)

To all whom it m/a/y concern:

Be it known that we, LYNN T. LEET, a citizen of Canada, and CLAUDE A. O.ROSELL, a

citizen of the United States, and residents of New York, in the countyof New York and State of New York, have invented a certain new anduseful Improvement in Indurating Stone, of which the following is aspecification.

This invention relates to a process of makingindurated stone, and refersmore particularly to the manner of induration, as will now be described.

At present there are in use two main methods of making induratedstone-the first, in

which dry and loose powdered material is placed in a form withoutpressure and in which the induration is effected by subjecting thematerial while in the form to the action of steam, hot water, or both;the second,

in which the material is moistened sufficiently to be capable of moldingby mechanical pressure, after which it is formed into articles ofdesired shape, which are then indurated by means of steam, orin rarecases by air. Our

invention relates to the second of these main methods.

In carrying out this process the constituent ingredients, such as sandand slaked 3o lime, are first mixed, and the mixture is thenmechanically molded into articles of desired shape. In this form thearticles are not strong enough to be immersed in water or an aqueoussolution without disintegration. To

5 overcome this difficulty, we first partly indurate the articles bymeans of steam for a short period-say two or three hours. After thistreatment the articles will be strong enough to stand immersion in aliquid for an indefi- 4o nite period. The partial induration by means ofsteam is preferably effected in a closed cylindrical vessel. As soon asthe articles are strong enough to stand immersion without disintegrationwater is introduced into the cylinder in quantity sufficient to coverall the partly indurated articles. The supply of steam to the cylinderis continued, so as to substantially maintain the same temperature andpressure as prevailed during the preliminary or partial hardening bymeans of steam. After the water has been introduced into the cylinderthe treatment is continued until the induration is completed, which maytake from three to ten hours, depending upon the temperature andpressure used. When the articles are thus soaked-that is, submerged andkept submerged-in the water heated to a high temperature and pressure,the induration proceeds faster than it does when subject to the actionof steam only at thesametemperatureand pressure. Besides, the soakinghas the advantage that in the liquor may be carried in solution orsuspension any of the known indurating agents, such as sodium chlorid,sodium carbonate, calcium chlorid, hydrochloric acid, alum, lime, 850.When lime is used in suspension in water, this mixture is generallycalled milk of lime, and this makes a good indurating agent.

What we claim as new is- 1. In the art of making indurated stone theimprovement which consists in mixing the constituentingredients,forminginto articles of desired shape, partly indurating the same bymeans of steam as far as steam induration is concerned, and completingthe induration by soaking the articles in a liquid at a high temperatureand pressure.

2. In the art of makingindurated stone, the improvement which consistsin mixing the constituent ingredients, forming into articles of desiredshape, partly indurating the same by means of steam as far as steaminduration is concerned, and completing the induration by soaking thearticles in a liquid containing hardeningmaterial, at a high temperatureI and pressure.

LYNN T. LEET. CLAUDE A. O. ROSELL.

Witnesses:

- B. F. KEINARD,

JOHN GALLAGHER.

